The CDC told consumers to throw away any romaine lettuce they may already have purchased. Restaurants should not serve it, stores should not sell it, and people should not buy it, no matter where or when the lettuce was grown. It doesn’t matter if it is chopped, whole head or part of a mix.

The unusually broad warning, issued just two days before Americans sit down for their Thanksgiving dinners, reflects the uncertainties about the origin and extent of the bacterial contamination. The CDC is not claiming that all romaine contains the dangerous bacteria — something the millions of people who have eaten the popular lettuce recently should bear in mind — but investigators don’t know precisely where, when or how the contamination happened.

Thus all romaine is suspect.

The CDC reported that 32 people in 11 states have become sick from eating contaminated romaine. Of those, 13 have been hospitalized, with one patient suffering from a form of kidney failure. The Public Health Agency of Canada has reported that 18 people have been infected with the same strain of E. coli. in Ontario and Quebec.

No deaths have been reported.

Romaine lettuce could be contaminated and should be thrown away, CDC advises. (karandaev/iStock)

“Consumers who have any type of romaine lettuce in their home should not eat it and should throw it away, even if some of it was eaten and no one has gotten sick,” the CDC said in the Food Safety Alert issued Tuesday afternoon.

“This advice includes all types or uses of romaine lettuce, such as whole heads of romaine, hearts of romaine, and bags and boxes of precut lettuce and salad mixes that contain romaine, including baby romaine, spring mix, and Caesar salad,” the CDC said. “If you do not know if the lettuce is romaine or whether a salad mix contains romaine, do not eat it and throw it away.”

The agency also advised consumers to wash and sanitize drawers and shelves where the lettuce was stored. People usually become sick within three or four days of consuming lettuce contaminated with the E. coli, according to the CDC.

Scott Gottlieb, commissioner of the Food and Drug Administration, said the looming Thanksgiving holiday weighed on the minds of federal officials as they prepared the food alert.

“I think we felt increased pressure to try to communicate earlier and more substantively with the public given that we know people are going to sit down for holiday meals,” Gottlieb said.

But he acknowledged that it is “frustrating and unfortunate” that the alert has to be so broad, covering all romaine lettuce. The federal agencies and the industry are trying to improve traceback techniques to narrow down the sources of outbreaks, he said. “We need to be able to get consumers more precise information about what they shouldn’t be eating, rather than these more general alerts.”

California has the highest number of reported illnesses, with 10, followed by Michigan with seven, New Jersey with three, Illinois, Massachusetts, New Hampshire and New York with two each, and the remainder in Connecticut, Maryland, Ohio and Wisconsin.

The Food and Drug Administration issued a statement saying it is making a special effort to test romaine for contamination across the country.

“The quick and aggressive steps we’re taking today are aimed at making sure we get ahead of this emerging outbreak, to reduce risk to consumers, and to help people protect themselves and their families from this foodborne illness outbreak. This is especially important ahead of the Thanksgiving holiday, when people will be sitting down for family meals,” Gottlieb said.

Five people died in the most recent major outbreak from contaminated romaine, which lasted from March to June of this year and led to 210 cases in 36 states. That outbreak was traced to the Yuma, Ariz., growing region, but investigators never conclusively determined the precise source.Gottlieb said the leading suspect is contaminated canal water used by multiple farms.

The latest outbreak does not appear to be connected to the Yuma outbreak. Rather, this outbreak involves a strain of E. coli that has the same genetic fingerprint as the one that causedillnesses late last year in both the United States and Canada. Canada linked its cases to romaine lettuce specifically, although the U.S. investigators said only that origin was in leafy greens. Once again, the precise origin was never determined. That outbreak was declared over in January.

The first illness from this outbreak was reported on Oct. 6. There are typically delays in reporting illnesses linked to E. coli outbreaks, and the CDC said cases from early November onward likely have not been logged by health officials.

But it’s striking that this year’s outbreak comes at roughly the same time as the one last year and with a similar fingerprint. The Canadian health agency noted that this “suggests there may be a reoccurring source of contamination.”

“If the 2017 outbreak and this outbreak are a genetic match, that should give the FDA an incredible window where this outbreak, where that lettuce, was grown, so they’re able to triangulate back to a particular area,” said prominent food-safety lawyer Bill Marler.

He said his firm has received many calls from people in the past month saying they’re suffering from E. coli, but they did not know this might be linked to a broad outbreak.

“I’m going to have to hire more lawyers,” Marler said.

E. coli is a bacteria found in the intestines of animals. It can contaminate a wide variety of agricultural products. People can become infected with E. coli and report no symptoms. Those who do get sick from E. coli usually recover without complications in 5 to 10 days. The illness can be spread from person to person through direct contact.

All three outbreaks — the current one, the one from Yuma and the one from last year — are caused by contamination of an E. coli strain known as O157:H7. It produces a Shiga toxin that in severe cases can lead to hemolytic uremic syndrome, a type of kidney failure.

Symptoms of infection from this strain include severe stomach cramps, bloody diarrhea and vomiting. Anyone suspecting they have been infected should see a doctor and have the case reported to a local health department.

Until the 1990s, most E. coli cases in humans came from eating contaminated hamburger. In more recent years, after reforms in the livestock industry, the outbreaks have been most often associated with leafy greens.

The FDA’s Gottlieb said the apparent increase in outbreaks could be misleading. Food is not less safe today than it was in the past, he said:

“It probably seems that there’s more outbreaks. What’s happening is that we’re getting much better at identifying outbreaks.”

Joel AchenbachJoel Achenbach covers science and politics for the National desk. He has been a staff writer for The Post since 1990.

Lena H. SunLena H. Sun is a national reporter for The Washington Post covering health with a special focus on public health and infectious disease. A longtime reporter at The Post, she has covered the Metro transit system, immigration, education and was a Beijing bureau chief. Follow

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